target sea lamprey for destruction
Biologists will try to rid Cheboygan River, local lakes
of destructive parasite's larvae
By Rich Adams
Cheboygan Daily Tribune
CHEBOYGAN - The search for the destructive sea lamprey
will continue this week.
A U.S. Fish and Wildlife Service assessment crew will
conduct work on the Cheboygan River during a period from
Tuesday until Sept. 4 to estimate the number of lampreys.
The work will be conducted in the lower mainstream, Burt
and Mullett lakes and the Black River.
In addition, crews will conduct assessment work on the
Carp Lake River in Emmet County that was scheduled earlier
this year but never completed, said Dennis Lavis with
the U.S. Fish and Wildlife Service station in Ludington.
"A first step in the control of sea lamprey is to
survey streams tributary to the Great Lakes," said
Sea lamprey first invaded the Great Lakes in the 1920s
and have been "a permanent, destructive element of
the fishery every since," he stated.
"Sea lamprey attach to fish with a suction-cup mouth,
rasp a hole through the fish's scales and skin, and feed
on blood and body fluids," Lavis explained. "The
average sea lamprey will destroy up to 40 pounds of fish
during its parasitic stage."
Sea lampreys prey on all species of large Great Lakes
fish such as lake trout, salmon, rainbow trout (steelhead),
whitefish, chubs, burbot, walleye, catfish, and even sturgeon.
Sea lampreys have had an serious negative impact on the
Great Lakes fishery, according to the Great Lakes Fishery
Commission Web site at www.glfc.org .
"Because sea lampreys did not evolve with naturally
occurring Great Lakes fish species, their aggressive,
predaceous behavior gave them a strong advantage over
their native fish prey. Their aggressive feeding behavior
contributed significantly to the collapse of fish species
that were the economic mainstay of a vibrant Great Lakes
fishery," states the Web site. "For example,
before sea lampreys entered the Great Lakes, Canada and
the United States harvested about 15 million pounds of
lake trout in lakes Huron and Superior annually. By the
early 1960s, the catch was only about 300,000 pounds.
The fishery was devastated."
Sea lamprey hatch from eggs laid by adult lampreys in
gravel nests, and drift into silty bottom areas where
they burrow and live for several years, Lavis said. Also,
larvae sometimes drift out of streams and settle in the
immediate offshore areas near stream mouths. Failure to
detect and eliminate larvae allows the lampreys to transform
into parasitic adults and kill Great Lakes fish.
Lavis said fishery biologists and technicians conduct
surveys for sea lamprey larvae in hundreds of streams
"Most surveys are conducted by electrofishing, but
in deep waters crews use Bayluscide 3.2 percent granula
sea lamprey larvicide, a chemical approved by the U.S.
Environmental Protection Agency and Health Canada Pest
Management Regulatory Agency," Lavis stated. "This
lampricide is specially formulated onto sand granules
and covered with a time-release coating. The formulation
is sprayed over a measured surface area of water, where
it sinks to the bottom, rapidly dissolves and causes the
larval sea lampreys to leave their burrows and swim to
the surface, where they are collected."